Republican presidential candidate Donald Trump speaks in front of a row of California state and American flags at a campaign rally on June 2, 2016 in San Jose, California. (Elijah Nouvelage/Getty Images)

A growing number of Republicans are publicly criticizing likely GOP presidential nominee Donald Trump for insisting that federal judge Gonzalo Curiel cannot objectively rule on two lawsuits against Trump University because the judge has Mexican heritage.

Legal expert David Post tells Here & Now's Robin Young that the First Amendment protects Trump's right to say anything he wants about the judge or the court system, but voters must consider what it means for a presidential candidate to attack judicial independence and the rule of law.

Interview Highlights: David Post

On the legal avenues available for criticizing a judge

"[Trump] can say what he wants to. As a private citizen, he has a First Amendment right just as you do or I do to criticize the judge to say the judge is unfair because he's Mexican-American. If that's what he believes he has a right to say that, and he can't be punished for saying that."

"Contempt of court is a much narrower concept. The most common contempt citation is when you defy a specific order of the court to do something or not do something. If you were ordered to produce documents and you do not produce them, the court can hold you in contempt. If you are ordered to come as a witness and you do not come, Trump has not defied any order of the court, and so he's not in contempt of court in that sense."

On Trump’s comments about the legal system

"It raises the prospect that President Trump, remember President Trump's job will be to enforce the law as it is interpreted by the courts. And this to me, and to many people, this raises the unpleasant prospect that he's setting us up for - if the court were to rule against him and if he were president - where he would tear up the order and say, 'Come get me. Come get my money.'"

"If Mr. Trump wants to have a debate about the legal system and its flaws - there are many of them - then that's terrific. But that's not what he's doing here. He is attacking the integrity of the system itself."

David Post

On how authoritarian leaders have targeted the judiciary

"The first thing they go after is an impartial judiciary, Venezuela being a most recent example - a country with a long democratic tradition that the judges were cowed into, they were terrified and thrown in jail. The second thing they do of course is they go after their political opponents, which Trump did the next day. Any fears one had about Trump's language in this were exacerbated when, two days later, he goes to another rally and he says Hillary Clinton is guilty and she should go to jail. That's the second thing authoritarians do - they throw their opponents in jail, it does happen. And for him to even suggest that for someone who hasn't been charged with a crime, and who's being investigated right now and who’s running against him in the coming election, is breathtaking."

On potential legal maneuvering on Trump’s part

"If Mr. Trump wants to have a debate about the legal system and its flaws - there are many of them - then that's terrific. But that's not what he's doing here. He is attacking the integrity of the system itself. And if he's president, he's part of that system. He's responsible for upholding that system, and it's worrisome that he might not do that."